Tube bending tool



1968 E. J. ZAHURANEC ETAL 3,417,94

TUBE BENDING TOOL Filed Sept. 30, 1966 2 Sheets-Sheet l INVENTORS EMERY J. ZAHURANEC & BY ZOLTAN SZOHATZKY E g/ 5m ,9

ATTORNEYS ec. 24, was

Filed Sept. 30, 1966 E. J. ZAHURANEC ET AL TUBE BENDING TOOL 2 Sheets-She et 2 INVENTORS EMERY J. ZAHURANEC 8 ZOLTAN SZOHATZKY ATTORNYS United States Patent 3,417,594 TUBE BENDING TOOL Emery J. Zahuranec, Solon, and Zoltan Szohatzky,

Mentor, Ohio, assignors to Crawford Fitting Company, Solon, Ohio, a corporation of Ohio Filed Sept. 30, 1966, Ser. No. 583,301 11 Claims. (Cl. 72-318) ABSTRACT OF THE DISCLOSURE A tube bending tool having a base, a shaft rotatably supported on the base, a forming mandrel secured to said shaft, an elongated bar secured to one end to said forming mandrel for rotation therewith an a tube abutment block. The tube abutment block is mounted on said bar for movement in a multiplicity of directions for the purpose of accommdating a tube when forming bends in various planes. The tube abutment block is capable of movement about a first axis of rotation coincident with the longitudinal axis of said bar, movement about a second axis of rotation parallel to the longitudinal axis of said bar, and movement in a line of travel parallel to the longitudinal axis of said bar.

This invention relates to improvements in hand operated tube bending tools and more particularly relates to an improved design of the tool such that compound bends may be placed in a length of tubing.

Various types of hand operated tube bending toolshave been devised. Samples of these are U.S. Patent No. 3,004,

583 and U.S. Patent No. 3,236,082. As illustrated in these patents, the tube is inserted in the tube bending tool and the end of the tube is drawn around a mandrel to form the desired bend. Although the angle of the bend in the tube may be varied, these prior art tools are restricted to placing bends in the tube in but a single plane.

It is an object of this invention to provide a tube bending tool in which compound bends may be placed in a tube.

It is a more specific object of the invention to provide a tube bending tool having a tube abutment means with a universal adjustment to accommodate bends in various planes.

More particularly, the invention comprises a forming roll or mandrel around which the tube is to be bent. Attached to the mandrel is an elongated bar and adjustably positioned along the length of the bar is a tube abutment means.

The tube abutment means comprises a clamping jaw with means securing the jaw to the bar for movement relative thereto. A support rod is carried by the jaw and a support member carried by the rod. A tube abutment block is secured to the support member. The clamping jaw is capable of movement both lon itudinally and circumferentially of the bar. The support member is supported on the support rod for movement relative to the rod and tube abutment block is likewise supported for movement relative to the support member.

Referring to the drawings:

FIG. 1 is a partial top plan view of a tube bending tool;

FIG. 2 is a perspective view of one embodiment of the tube abutment means;

FIG. 3 is a sectional view taken along line 33 of FIG. 2;

FIG. 4 is a perspective view of an alternative embodiment of the tube abutment means;

FIG. 5 is a sectional view taken along lines 55 of FIG. 4.

The instant invention is shown in conjunction with a tube bending tool of the type illustrated in U.S. Patent No. 3,004,583 to which reference is hereby made for a more complete description of one type of tube bending tool with which the instant invention may be used.

FIG. 1 shows, in brief, a tube bending tool, designated generally by the reference numeral 10, which comprises a cover plate 11 with a shaft 12 extending up through the cover plate. A tube forming roll or mandrel 13 is secured to the shaft 12 for rotation therewith. A peripheral groove 14 is formed in the mandrel 13 with the groove being adapted to receive a tube. A gear 15 is secured to the shaft 12, with the gear 15 being in meshing engagement with a pinion 16. A handle 17 is operable to rotate the pinion 16 thereby to transmit rotation to the shaft 12 and the mandrel 13. Coaxial with the pinion 16 is a roller 18 which has a circumferential groove 19 also adapted to receive the tubing. An elongated bar 20 is secured to the mandrel 13 with a hook 21 pivotally secured on the bar 20. Tube abutment means, indicated generally by the reference numeral 22, is supported on the bar 20.

As is more fully described in the above-mentioned Patent No. 3,004,583, the tube bending tool is employed by inserting a length of tubing between the roller 18 and the mandrel 13, with the tube being received in the grooves 14 and 19. The end of the tubing abuts the tube abutment means 22 and the hook 21 embraces the circumference of the tubing to retain the tubing in engagement with the roller 18 and the mandrel 13 during the bending operation. Rotation of the handle 17 causes rotation of the mandrel 13 and pivots the elongated bar 20 about the shaft 12 as a center of axis of rotation. The book 21 on bar 20 draws the tubing about the mandrel 13 thereby imparting a bend in the tubing. An adjustable stop 23 may be employed to limit the degree of bend placed in the tubing.

One embodiment of the tube abutment means which comprises the instant invention is illustrated in FIG. 2. The tube abutment means 22 includes a split clamping jaw received over the bar 20. A set screw 31 is employed to clamp the jaw on the bar 20. A support member 33 having an aperture 34 is received over the rod 32. Like the jaw 30, the support member 33 has a split construction so that compression of the split arms will cause frictional engagement of the member against the rod 32 to position the member along the length of the rod. A tube abutment block 35 having bifurcated arms 35a, 35b is provided with a stem 36 which is received in an aperture 38 extending through the support member 33. Threads 37 are provided on the projecting end of the stem 36 and a nut or adjusting knob 39 is threadably engaged over the stem 36. Each bifurcated arm of the block 35 has corrugations 40 along the interior surfaces thereof to provide a means for receiving tubes of varying diameters.

With the above described abutment means, it is readily apparent that with but two adjustments, the abutment means may be adjusted in at least five ways. Thus, by releasing the set screw 31, the jaw 30 may be pivoted about the bar 20 in the direction of the arrow 41 and. moved longitudinally of the bar 20 in the direction of the arrow 42. Adjusting knob 39 controls pivoting of the support member 33 about the rod 32 in the direction of the arrow 43 and also controls sliding movement of the member 33 along the rod 32 in the direction of the arrow 44. The adjusting knob 39 also controls the angular position of the block 35 relative to the support member 33, as indicated by the arrow 45.

It is also believed to be apparent that with the above described tube abutment means, it is possible to employ an otherwise conventional tube bending tool to place compound bends in a length of tubing. As diagrammatically illustrated in FIG. 2, the tubing T has a bend already placed in it by using a tube bending tool in the conventional manner. Assuming it is desired to place a second bend in the tubing in a plane other than the plane of the original bend, the operator need merely adjust the elements of the tube abutment means 22 so that the end of the tubing T will be received in the tube abutment block 35 and held in this position while the tube bending tool is employed in the conventional manner.

Referring to the embodiment of FIG. 4, the tube abutment means comprises a split clamping jaw 50 similar to the jaw 30 in the embodiment of FIG. 2. An adjusting knob 51 controls the positioning of the jaw along the bar 20. A support rod 52 is carried by the jaw 50, with the rod 52 extending substantially parallel to the longitudinal axis of the bar 20. A first support member 53 is rotatably positioned over the rod 52 with an adjusting knob 54 being threaded over the end of the rod 52. A second support rod 55 is carried by the support member 53 with an elongated secondary support member 56 being rotatably received over the rod 55. A third adjusting knob 57 is threaded over the end of the rod 55. A slot 58 is formed in the support member 56, with the slot 58 being substantially parallel to the rod 55. A tube abutment block 60 having a stem 61 projecting from one side thereof is provided with the stem 61 projecting through the slot 58. A fourth adjusting knob is threaded over the stem 61. A substantially V-shaped recess or groove 63 is formed in the block 60 and is adapted to receive the periphery of a tube therein.

The embodiment of FIG. 4 accomplishes essentially the same function as the embodiment of FIG. 2 and provides at least five separate adjustments of the parts of the tube abutment means to accommodate an infinite number of bends in a tube. However, the embodiment of FIG. 4 does require the use of four adjusting knobs as compared to only the two adjustments necessary in the embodiment of FIG. 2.

We claim:

1. A tube bending tool comprising:

a base;

a shaft rotatably supported on said base;

a forming mandrel secured to said shaft;

an elongated bar secured at one end to said forming mandrel;

tube abutment means supported on said bar;

said tube abutment means comprising a clamping jaw;

means securing said jaw to said bar for movement relative thereto;

a support rod carried by said jaw;

a tube abutment block having a tube supporting surface thereon;

a support member carried by said rod; and

means securing said block to said support member.

2. The tool of claim 1 wherein said securing means for said block permits movement of said block toward and away from said jaw.

3. The tool of claim 2 wherein said support rod extends substantially radially of said bar;

said support member being rotatably and slidably received over said rod.

4. The tool of claim 3 wherein said securing means for said block permits pivotal movement of said block relative to said support member.

5. The tool of claim 1 wherein said support rod is substantially parallel to said bar;

said support member being rotatably received over said rod;

an elongated slot formed in said support member;

said securing means for said block extending through said slot.

6. The tool of claim wherein said support member is formed in two parts with said slot being formed in one part of said support member and the other part of said support member being received over said rod; and

means supporting said one part of said suport member on said other part for movement relative thereto. 7. The tool of claim 1 wherein said securing means for said jaw permits movement of said jaw both longi- 5 tudinally and circumferentially of said bar;

said support member including an aperture receiving said support rod and clamping arms adapted to grip said rod; an aperture through said clamping arms; a bolt received in said aperture in said arms; one end of said bolt being secured to said abutment block; the other end of said bolt having threads formed thereon; and a locking nut threaded over said bolt. 8. The combination of claim 1 wherein said block has bifurcated arms;

said tube supporting surface comprising corrugations on the interior surfaces of said arms to receive tubes of various diameters. 9. The combination of claim 1 wherein said support member includes an elongated slot formed therein;

a bolt received in the slot; one end of said bolt being secured to said abutment block;

the other end of said bolt having threads formed thereon; and a locking nut threaded over said bolt. 10. In a tube bending tool having a base; a shaft rotatably supported on said base; a forming mandrel secured to said shaft; and elongated bar secured at one end to said forming mandrel for rotation therewith; the improvement comprising:

a tube abutment block adapted to engage a piece of tubing; means suporting said tube abutment block on said bar for movement in a multiplicity of directions including:

(a) movement toward and away from said bar; (b) movement about a first axis of rotation parallel to the longitudinal axis of said bar; and (c) movement about a second axis of rotation different from said first axis of rotation. 11. In a tube bending tool having a base; a shaft rotatably supported on said base; a forming mandrel secured to said shaft; and an elongated bar secured at one end to said forming mandrel for rotation therewith; the improvement comprising:

a tube abutment block adapted to engage a piece of tubing;

means supporting said tube abutment block on said bar for movement in a multiplicity of directions relative to said bar including: (a) movement about a first axis of rotation coincident with the longitudinal axis of said bar; (b) movement in a line of travel parallel to the longitudinal axis of said bar; (0) movement about a second axis of rotation parallel to the longitudinal axis of said bar.

References Cited UNITED STATES PATENTS 2,341,178 2/1944 Duer 72l49 X 65 2,413,523 12/1946 Shaw 72319 3,004,583 10/1961 Zuccala et al. 72150 3,236,082 2/1966 Beck et a1. 72l49 CHARLES W. LANHAM, Primary Examiner. E. SUTTON, Assistant Examiner.

US. Cl. X.R. 

